The invention relates to an apparatus for conducting the catalytic oxidation of gaseous sulfur compounds, such as sulfur dioxide, to sulfur trioxide, comprising a reaction housing containing a plurality of tubes located between tube plates, and having domes for the feeding, guidance, and discharging of the reaction gas to and/or from individual tube groups. All of the tubes, or only a portion thereof, contain a catalyst, and all of the tubes are surrounded by a flow of liquid heat-transport agent. The apparatus of the invention relates to an apparatus such as is disclosed in West German Patent No. 2,711,897.
The apparatus according to the cited German patent is characterized in that individual tube groups are each associated with their own domes, or dome chambers defined within a dome by respective partitions. The domes or dome chambers with their catalyst-filled tube groups are connected in series with respect to the flow relationships, and the space around the tubes is filled with a liquid heat-transfer medium and is connected to a circulation system for the heat-transfer medium comprising at least one heat exchanger. In this conventional apparatus, the heat exchanger, which is the means for the removal of the sum total of the reaction heat developed in the reactor, is arranged outside of the reactor, and the heat-transport agent must be passed back and forth through pipelines between the reactor and the heat exchanger. This results in increased heat losses to the surroundings. In addition, it is difficult to maintain the temperature of the heat-transport agent flowing around the reactor tubes, and accordingly also the temperature of the reaction gas while flowing through the catalyst-filled tubes, within narrow limits.